It has become common practice in the electrical industry to produce electrical harnesses by means of semi-automatic or fully automatic harness making machines of the general types shown, for example in U.S. Pat. Nos. 4,136,440, 4,043,017, and 4,235,015. Machines of the general type shown in these U.S. patents have a wire feeding means in the form of a reciprocable shuttle which pulls wires from endless wire sources, such as barrels or reels, and presents the leading ends of the wires directly to a connecting or terminating station at which the ends of the wires are connected to terminals in a multi-contact electrical connector. U.S. Pat. No. 4,136,440 also shows wire cutting means and insulation stripping means for stripping the ends of the wires, while U.S. Pat. No. 4,043,017 shows a second connecting or terminating station for connecting trailing ends of the wires to terminals in a second connector. U.S. Pat. No. 4,136,440 also shows a mechanism on a harness making machine for producing harnesses having leads of varying lengths, rather than leads of uniform lengths, extending from the connector which is installed on the leading ends of the wires. Leads of varying lengths in the finished harness are produced, in accordance with the teachings of the U.S. Pat. No. 4,136,440, by lengthening members which move against the wires laterally of their axes and from loops in the individual wires to produce varying lengths as required in the harness.
Harness making machines of the type described above are receiving widespread acceptance in the electrical industry and are constantly being improved to permit added operations on the connector and wires during manufacture, to permit the use of connectors having terminals on increasingly closer centers, and in general, to improve the reliability and speed of these machines. The present invention is directed to the achievement of an improved harness making machine which is capable of operating at a relatively high speed, which has improved wire feeding means, and which has an improved means for producing leads of varying lengths in the finished harness. The invention is further directed to the achievement of a machine which is relatively compact and which has the capability of stripping insulation from both ends of the leads of the harness. By virtue of this feature, a harness making machine in accordance with the invention can be equipped with terminal crimping means so that terminals are crimped onto the ends of the wires.
A preferred embodiment of the invention comprises wire feeding means in the form of individual feed rolls for each of the wires in the completed harness. The individual sets of feed rolls are controlled by a controlling means, as disclosed in U.S. Pat. No. 4,043,494 (which is hereby incorporated by reference in its entirety) in a manner such that leads of varying lengths can be produced during a single operating cycle. The wires are fed from the sources through upstream and downstream wire guides which have opposed ends that are against each other during at least the initial portion of the feeding operation. These wire guides are moved apart so that portions of the fed wires are exposed in the gap which is formed between the opposed ends of the guides. A transfer device is provided which moves into this gap adjacent to the downstream wire guide and grips the wires at the end of the feeding portion of the cycle. The wires are cut by cutting blades which are located in the gap between the wire guides and thereafter the trailing ends of the resulting leads, that is portions of the wires extending downstream from the plane of cutting, are transferred to a wire connecting station. A connector is then installed on the trailing ends by a connecting means which connects the wires to terminals in the connector. The wire cutters are contained in a die set and, if desired, insulation cutters can also be mounted in the die set on each side of the wire cutters so that the insulation of the trailing ends of the leads is cut, as well as the insulation on the leading ends of the wires extending from the feed rolls. The die set and the upstream wire guide are capable of moving relative to the cut ends of the leads and wires in a way which will permit stripping of the trailing ends of the leads and the leading ends off the wires.